KABUL, Afghanistan – The Soviet Union couldn’t win in Afghanistan, and now the United States is about to have something in common with that futile campaign: nine years, 50 days.

As of today, the U.S.-led coalition has been fighting in this South Asian country for as long as the Soviets did in their humbling attempt to build up a socialist state. The two invasions had different goals — and dramatically different body counts — but whether they have significantly different outcomes remains to be seen.

What started out as a quick war on Oct. 7, 2001, by the United States and its allies to wipe out al-Qaida leader Osama bin Laden and the Taliban has instead turned into a long and slogging campaign. Now about 100,000 NATO troops are fighting a burgeoning insurgency while trying to support and cultivate a nascent democracy.

A Pentagon-led assessment released this week described the progress made since the United States injected 30,000 more troops into Afghanistan earlier this year as fragile.

The top U.S. military commander in Afghanistan, Gen. David Petraeus, has said NATO’s core objective is to ensure that Afghanistan “is never again a sanctuary to al-Qaida or other transnational extremists that it was prior to 9/11.”

He said the only way to achieve that goal is “to help Afghanistan develop the ability to secure and govern itself. Now not to the levels of Switzerland in 10 years or less, but to a level that is good enough for Afghanistan.”

When the Soviet Union invaded Afghanistan on Dec. 27, 1979, its stated goal was to transform Afghanistan into a modern socialist state. The Soviets sought to prop up a communist regime that was facing a popular uprising, but left largely defeated on Feb. 15, 1989.

In 1992, the pro-Moscow government of Mohammad Najibullah collapsed and U.S.-backed rebels took power. The Taliban eventually seized Kabul after a civil war that killed thousands more. It ruled with a strict interpretation of Islamic law until it was ousted by the U.S.-led invasion.

Nader Nadery, an Afghan analyst who has studied the Soviet and U.S. invasions, said “the time may be the same” for the two conflicts, “but conditions are not similar.”

More than a million civilians died as Soviet forces propping up the government of Babrak Karmal waged a massive war against anti-communist mujahedeen forces.

Michael O’Hanlon, a senior fellow at the Brookings Institution think tank and Afghanistan expert, said NATO forces have killed fewer than 10,000 civilians and a comparable number of insurgents.

The allied military presence has also been far smaller and more targeted. Even now, nearly all operations are restricted to the south and east of the country where the insurgency is most active.